Powered winches

ABSTRACT

This invention relates to powered winches, preferably electrically powered, comprising in combination a housing, a plurality of rotatable drums, a worm and worm wheel drive by means of which the rotatable drums are rotated from a power source, a diaphram dividing the winch housing interior into an oil-present drive part and an oil-free cable part, and a cable tensioning means, the winch being such that in use a cable passes through the winch after engaging said rotatable drums and said cable tensioning means, said cable tensioning means being such as to act on constantly differing adjacent portions of the cable, and said portions of the cable always being of the same length.

1451 Aug. 14,1973

United States Patent 1191 Coombs E m F wwm .M mm m 3 3 E mmm m 6 2 132 .m n 3 2 P. e m .m uh um w "I m m dh r05 .mo m Cwm C e 8 27m m mm O W WCB E E m m w mm MG 5 U [22] Filed: Mar. 12, 1971 Assistant Examiner-Merle F. Maffei Attorney-Dowel] and Dowell [211 App]. 1%.; 123,835

ABSTRACT This invention relates to powered winches, preferably electrically powered, comprising in combination a housing, a plurality of rotatable drums, a worm and worm wheel drive by means of which the rotatable drums are rotated from a power source, a dia .l. 7 s 76 7 mmm 0 w nwl, 5 0 8 58 n "n 4 4 5 M5 2 2 mun4 u 8 1 I u/ n. 4 "nus "2 m"... "mm L m C d td i UmF 1]] 2 8 555 [.ll

phram di- [56] Reierenc Cited viding the winch housing interior into an oil-present UNITED STATES PATENTS drive part and an oil-free cable part, and a cable tensioning means, the winch being such thatin use a cable passes through the winch after engaging said rotatable drums and said cable tensioning means, said cable ten sioning means being such as to act on constantly differing adjacent portions of the cable, and said portions of the cable always being, of the same length.

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.I J WSMSK JK 8.4038282 23666323 99999999 llllllll l/l/l/l/ 82 52282 ll 1 323532. ..53 8 247989 w 25286 2 8.428 989 1 lvl2 lll 3 owing-4 Drawing Figures POWERED f time spent by an operator in working the hand winches may be as much as 50 per cent of a working day. I Electrically powered winches have hitherto been available for elevating stagings but these winches have not generally replaced the hand winches because the electrically powered winches are expensive to manufactiire and purchase and are very large and cumbersome. The large size of these known electrically powered winches and their consequent heavy weight is due to the fact that a cable to be reeled has to be wound on a drum forming part of the winch. 7

It is an aim of this invention to provide a powered winch which is not subject to the above mentioned dis advantages and which is able to climb a cable with the cable passing through the winch. I v

To this end, a powered winch in accordancewitli the invention comprises, in combination, a housing, a plurality of rotatable drums, a worm and worm wheel drive by meanswhich the rotatable drums are rotated froma power" source, a diaphragm dividing the winch housing interior into an oil-present drive part and an oil-free cable part, and a cable tensioning means, the

winch beingsuch that in use a cable passes through the winch. afternengaging said rotatable drums and said cable tensioning means,fsaidcable tensioning means being suchxas to actjon constantly differing adjacent portionsofthe cable, andsaid portions of the'cable al-l' Waysbeing of the same-length,

Preferably, the winch has two rotatable druriis consti tuting'a' first drum and al second drum. The periphery of each rotatable drum is preferably provided with one or more cable-receiving tracks to ensure that the cable is in contact-witha 'large surface area of the drum, thus providing?! large amount of grip between the cable and the track in tracks when the drums are rotated. in one embodiment of the" invention, the first and second drums "have' two cable-receiving tracks Guide plates are preferably positioned near the drums to ensure that the cables remain firmly situated in the cable tracks.

The cable tensioning means may be a pressure plate, for example a multi-spring biased pressure plate similar to .a swash plate which combines with one of the rotatable drums to form a single cable receiving track. In this case, the pressure plate will rotate while gripping the cable in the said track, thereby maintaining the cable under tension. As the winch climbs the cable, the free end of the cable will leave the track pass through the winch housing and will dangle from the winch.

The winches of this invention will preferably be provided with cable guiding means for guiding the cable at an appropriate angle to the rotatable drums. They may also be provided with further cable guiding means for guiding the cable as'it leaves the winch via the cable tensioning means:

A preferred embodiment of this invention is one in which the winch includes an electric motor for driving the rotatable drums and the cable tensioning means, for

example the pressure plate. The electric motor is easily arranged to drive the two or more rotatable drumsaiid the cable tensioning means, e.g.- pressure plate, by using a chain drive, a reduction gearihg'system and the worm and worm wheel. There maybe three sets of gearing effecting power reduction to the primary drum in which case the second drum may be driven by an endless chain which endless chain is driven by the first drum. I

Although the winches are presently constructed to have a safety factor of 18:1, they are preferably constructed to include one or more auxiliary safety devices.

for preventing uncontrolled which descent when, the winch is in use. For example, the winches may include two such safety devices, one of which may be a dead man's lever and the other of which may be a mechanical cable gripping device. The dead mans lever will usually be such that when it is not held in an off position by the operator, it will automatically return to a position which cuts out the winch power source and causes a brake to be applied. The bake may be an electromagnetic brake. The mechanical cable. gripping device is suitably attached to the upper part of the winch housing. Y l I The various winch components may be of such size and construction that they can easily be housed'in a single integral casing. For example, a complete winch may weight approximately only one; and a half cwts. and

may be housed in a flat rectangular casing approximately 3 feet long, one foot wide and one and a half feet fall. In this case, the electric motor may be attached to the outside of the housing. Preferably, the casing is appropriately apertured or provided with other suitable means by which the winch can be quickly and easily attached to staging.

he drivepart of the winch, for example the worm and worm wheel; the chain drive and reduction gearing, should be well lubricated to minimize wear. However the lubricant should not be to contact the cable or the cable-contacting surface of the rotatable drums and the pressure plate since a high coefficient of friction is desired. Accordingly, it has been found desirable to form the winch into an oil-present drive part and an oil free cable part, the two parts being separated by a diaphragm. The casing may be provided with a conduit for introducing lubricant to appropriate parts. In one embodiment of the invention, the winches are provided with a cam arrangement which drives an oil pump for effecting the. lubrication.

In order that the winches of this invention may be as light as possible it is preferred to manufacture many of the winch parts from an aluminium alloy. For example, the winch .casingmay be made from a heat treated aluminium alloy. I

The rotatable drums may be made from steel, preferably high tensile,- heat treated. steel. The rotatable drums are normally hollow drums to provide for a minimization in weight and cost.

The winches may be fitted with advantage to the staging which is the subject of copending application Ser. No. 811,876 filed concurrently with this Application. The winches will usually be positioned at predeteris equally distributed to the winches.

An embodiment of the invention will now be described by way of example'with reference to the accompanying drawings in which:

FIG. 1 is a top cross-sectional view take on line A-A of FIG. 3 of an electrically powered winch in accordance with the invention;

FIG. 2 is a cross-sectional view-on the line 8-8 shown in FIG. 1;

FIG. 3 is a front cross-sectional view of the winch shown in FIG. 1 and also shows a dead mans lever; and

FIG. 4 is a cross-sectional view on the line C-C shownin FIG. 3.

Referring to the drawings, a casing 2 houses a hollow first drum 4 and a hollow second drum 6. The drum 4 rotates on a bearing 8 on a shaft 10 fixed to the casing 2 and the drum'6 rotates on a bearing 12 on a shaft 14 also fixed to the casing 2. The drums 4 and 6 are provided with cable-receiving tracks 16 and 18 respectively.

A'pressure plate 20 (FIG. 1) is attached to one end of the drum 4 by spring loaded screws 21. Thus, a single cable-receiving track is formed between the pressure plate 20 and the drum 4. As will be explained in more detail hereinafter, the pressure plate 20 acts on the cable with a force which is due to the spring loaded screws 21. Obviously, this force is increased byscrewing the screws further into the end of the drum 4.

The drums 4 and 6 and the pressure plate 20 are operated by a 3 horse power electric motor 22 attached to the outside of the casing 2 at a point adjacent the drum 6. The electric motor 22 effects the drive of the drum 4 through a first set of reduction gearing 26, a second set of reduction gearing 28, and a worm 31 (shown in phantom in FIG. 3) positioned between the two sets of reduction gearing 26,28. The worm in turn drives a worm-wheel 33 attached by screws 35 to the drum 4. The portion of the worm 31 with respect to the drum 6 is shown most clearly in FIG. 2 and it will be noted that the worm 31 is mounted in bearings 31A and 313 by means of nuts 31C and 31D. As shown in FIG. 1, the drum 6 is driven by an endless chain 24 which passes around the said worm-wheel 33 (FIG. 3) and a cog-wheel 37 which is attached by screws 39 to the drum 6. v

A cable '(not shown) is'guided to the drum 4 by means of an annular cable guide 39 shown in FIG. 3. The cable may make 1% turns on the drum 4 in the cable-receiving track 16 and it may then pass to the drum 6. The cable may pass several times between the drums 4 and 6 and make at least three turns on thedrum 6. From the drum 6 the cable passes to the single cablereceiving track l9 formed between the pressure plate 20 and the drum 4. In this single cable-receiving track, the cable may make three quarters of a revolution before leaving the track and passing out of the casing 2.

In order to lubricate the driving parts, the winch is provided with an oil pump 29 and an oil breather 30. I

As most clearly shown in FIG. 3, the oil pump 29 is worked by means of an oil pump cam 32 rotatable with the drums 6. As the cam 32 rotates, a roller 41 fixed to one end of a toggle linkage 43 rides over the humps and the other end 45 of the toggle linkage moves against pressure from a spring 47 to cause oil to be squirted through the oil conduit 49 to the oil opening 51 near the reduction gearing 26. Oil is prevented from wandering onto the drum and pressure plate-cablecontacting surfaces by means of an appropriate diaphragm and an oil seal. Part of the diaphragm is shown at 53 in FIG. 2 extending between the'top and bottom of the housing 2.

The winch casing 2 is provided with lugs 34 so that it can be bolted to staging (not shown).

In use the electric motor 22 acts through the two sets of reduction gearing 26 and 28, and causes the worm 31 shown in FIG. 3 to rotate and mesh with the worm wheel 33 attached to the drum 4. Rotation of the worm-wheel 33 causes the drum 4 and endless chain 24 to rotate. In turn rotation of the endless chain 24 is transmitted to the drum 6 via the cog-wheel 37 attached to the drum 6, the two drums thus rotating at the same speed. The pressure plate 20 is directly attached to the drum 4 and rotates with it.

The cable makes the desired number of turns around the drums 4, 6 and then passes, as explained above, to the single cable-receiving track 19 formed between the pressure plate 20 and the outside of the drum 4. Whilst the cable is in this rotating track, the springs 21 cause the cable to be gripped with a predeterminable force. Thus, the cable is constantly placed under tension from within the winch by the pressure plate and the pressure plate only acts on that part of the cable that is within the said single cable-receiving track 19. In other words, during operation of the winch, constantly differing adjacent portions of the cable will be acted upon by the winch but these portions will always be of the same length. If the cable is fixed to the top of a structure and is hanging therefrom, the pressing/rotating action of the pressure plate will cause the winch to climb the cable and those portions of the cable that have been acted upon by the pressure plate will merely leave the single cable-receiving track and will pass out through the winch casing. The cable can then merely hang from the winch as the winch is climbing and there is no need for bulky cable storage drums. If the cable is attached to an object to be moved and the position of the winch is fixed, the pressing/rotating action of the pressure plate will still cause the cable to be pulled through the winch, thus'pulling the said object towards the. winch. Again, there is no need for bulky cable storage drums. Obviously the pressure plate does not exert a pull on the cable which is equal to that required to directly pull the winch upwards or to directly pull an object along. Because of the friction existing between the cable and the two drums 4, 6 the pressure plate only has to exert a relatively soft pull on the cable.

' The use of a worm and worm wheel arrangement for driving the drum 4 effectively provides the winch with a simple, efficient, and built-in safety feature. More specifically, the use of a worm and worm wheel arrangement means that the drum 4 can only be rotated by the worm 31 rotating the worm wheel 33 attached to the drum 4. It is not possible for the drum 4 and attached worm-wheel 33 to rotate and thereby drive the worm 31. Thus, the worm 31 can be rotated in a clockwise or anti-clockwise direction to cause the drums 4,

6 to rotate in one direction when the winch is to climb a suspended cable and to cause the drums 4, 6 to rotate in the other'direction when the winch is to descent a suspended cable. The winch ascent or descent will always be controlled. If at any point during the winch ascent or descent, the electric motor 22 should fail, uncontrolled descent of the winch will be prevented because the cable will not be able to rotate the drums 4, 6 because the worm-wheel 33 attached to the drum 4 will merely lock into the worm 31. Thus, the winch drive incorporates an automatic and robust safety device, thereby avoiding the cost of providing an auxiliary safety device if desired.

in FIG. 3, the winch is shown with a dead man's lever in position. The dead mans lever comprises a handle 100 which can be moved up and down from a normal position. When the handle 100 is in the normal position (shown in full lines) a cable gripping device 102 (shown diagrammatically in FIG. 3) grips the cable 104 and prevents it from passing therethrough. When the cable is held in the up or down positions shown in phantom in FIG. 3, the cable gripping device 102 allows the cable 104 to freely pass therethrough so that the winch can ascend or descend the cable 104. The handle 100 operates the device 102 via pivotted linkage members 106, 108, 109 and 110. Movement of the handle 100 also causes, via pivotted link arms 112 and 114, a switch 116 to be operated so that when the handle 100 is in its normal position and the device 102 is gripping the cable 104, the electric motor 22 is cut off.

i claim:

1. An electrically powered winch comprising in combination:

a housing;

first and second rotatable drums each having a periphery provided with cable-receiving tracks;

a worm and worm wheel drive by means of which one of the rotatable drums is rotated from an electric motor in one direction; and a sprocket and chain connected between the drums drives the other drum in the same direction;

combined operational andsafety means comprising a handle and safety lever which is moved one way from a normal non-operative position for winch ascent and which is moved the other way from said normal non-operative position for winch descent, and cable gripping means which grips the cable when the handle and safety lever is in the normal non-operative position but which releases the cable when the handle and safety lever is moved either way from said normal non-operative position to allow said winch ascent and descent;

a wall within the housing dividing the winch housing interior into an oil-present drive part and a oil-free cable part; and

a cable tensioning means constituted by a pressure plate which combines with one of the rotatable drums to form a single cable-receiving track;

the winch being such that in use a cable passes through the winch after engaging said rotatable drums and said cable tensioning means, said cable tensioning means being such as to act on constantly differing adjacent portions of the cable, and said portions of the cable always being of the same length.

2. A winch according to claim 1 having cable guiding means for guiding said cable at an appropriate angle to said rotatable drums.

3. A winch according to claim 1 in which the electric motor drives the rotatable drums and the cable tensioning means through a chain drive, a reduction gearing system and the worm and worm wheels.

i l I II i UNITED STATES ?ATENT UFFICE? I (IETHHJCATE r coRR cTmN Patent No. 3, 752, 442 Dated 'August 14', 1973 Invent WILLIAM cHARLEs 'COOMBS It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:

In the heading of the patent (first column) between lines 6 and 7 insert:

[30] Foreign Application Priority Date: 7

April 11, 1968 Great Britain N0. 17573-6/68 Signed and sealed this lZth day of March 1974.

(S Attest:

EDWARD M.FLETCHE R,JR. I C; MARSHALL DANN Attesting Officer; Commissioner of Patents FORM PO-105O uscoMM-oc shave-P69 U,S. GOVERIVUJIENT PRINTING OFFICE 1 19 69 0-:366-334 

1. An electrically powered winch comprising in combination: a housing; first and second rotatable drums each having a periphery provided with cable-receiving tracks; a worm and worm wheel drive by means of which one of the rotatable drums is rotated from an electric motor in one direction; and a sprocket and chain connected between the drums drives the other drum in the same direction; combined operational and safety means comprising a handle and safety lever which is moved one way from a normal non-operative position for winch ascent and which is moved the other way from said normal non-operative position for winch descent, and cable gripping means which grips the cable when the handle and safety lever is in the normal non-operative position but which releases the cable when the handle and safety lever is moved either way from said normal non-operative position to allow said winch ascent and descent; a wall within the housing dividing the winch housing interior into an oil-present drive part and a oil-free cable part; and a cable tensioning means constituted by a pressure plate which combines with one of the rotatable drums to form a single cable-receiving track; the winch being such that in use a cable passes through the winch after engaging said rotatable drums and said cable tensioning means, said cable tensioning means being such as to act on constantly differing adjacent portions of the cable, and said portions of the cable always being of the same length.
 2. A winch according to claim 1 having cable guiding means for guiding said cable at an appropriate angle to said rotatable drums.
 3. A winch according to claim 1 in which the electric motor drives the rotatable drums and the cable tensioning means through a chain drive, a reduction gearing system and the worm and worm wheels. 